判断tableView上下移

-(void)scrollViewWillBeginDragging:(UIScrollView*)scrollView{

lastContentOffset = scrollView.contentOffset.y;

}

-( void )scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {

if (scrollView.contentOffset.y > lastContentOffset )

{

//向上

topIV.hidden = YES;

NSLog(@"向上");

} else if (scrollView. contentOffset.y